Structures with curved surfaces, such as egg-shaped anaerobic digesters, have found widespread commercial use. Thus, for example, in an article entitled "Egg-shaped anaerobic digesters" (published by John P. Garvin et al. in the September, 1987 issue of "Pollution Engineering" magazine [Pudvan Publishing Company]), it is disclosed that "The use of steel egg-shaped anaerobic digesters is a well-developed and proven technology for the digestion of sewage sludge"
Egg-shaped anaerobic digesters are doubly curved, i.e., they present both vertically curved and circumferentially curved surfaces. Because of these doubly curved surfaces, anaerobic digesters are difficult to both cover and insulate properly.
It is an object of this invention to provide a structure containing an exterior surface which is both vertically and circumferentially curved and which is clad with a tensioned, fabric-containing cladding member which is not contiguous with the exterior surface of the structure.
It is another object of this invention to provide a relatively inexpensive process and apparatus for covering and insulating a structure with a curved exterior surface to provide efficient and durable protection to such structure.